Method and apparatus for stitching metal strip



Jan. 8, I935. J. BlGGE RT METHOD AND APPARATUS FOR STITCHING METAL STRIP Filed April 20, 1934 S-Sheets-Sheet l INVENTOR ATTORNEYJ wmvsssss I Jan. 8, 1935. J. BIGGERT METHOD AND APPARATUS FOR STITCHING METAL STRIP Filed April 20, 1934 5 Sheets-Sheet 2 IN VEN TOR W/TNE'JSES Xddw Jan. 8, 1935. J. BIGGERT 1,987,176

METHOD AND APPARATU FOR STITCHING METAL STRIP Filed April 20, 1934 5 Sheets-Sheet 3 WITNESSES VEN TOR 2 g g (2 zz A TTORNEY-S Jan. 8, 1935. J. BIGGERT 1 7 1,987,176

I METHOD AND APPARATUS FOR STITCHING METAL STRIP S l I i Q @i g r WITNESSES I INVENTOIF BY y/3 2 A TTORNEY8 Jan. 8, 1935.

J. B |GGERT 1,987,176

METHOD AND"'APPARATUS FOR STITCHING METAL STRIP.

Filed April 20, 1934 5 Sheets-Sheet 5 WITNfSSES 1 I INVENTOR lay/$41M Z ATTORNEYS Patented Jan. 8, 193 v v I UNITED STATES PATENT orrics METHODVAND APPARATUS FOR s'rrrcmNG METAL s'mrr John Biggert, Grafton, Pa., assignor to United Engineering & Foundry Company, Pittsburgh,

Pa., a corporation of Pennsylvania Application April 20, 1934, Serial No. 721,489 7 Claims. (01. 164-109) This invention relates to the handling and member 3 rigidly secured between the uprights treating of metal strip, and more particularly to and a plurality of cooperating movable die-forms a method and apparatus for connecting, or stitching elements 4, the number of which depends upon ing, the ends of two or more pieces of such matethe number of punches employed in the machine 5 rial together to facilitate the handling and manipwhich in turn may vary with the width of the 5 ulation thereof in various continuous treating machine or the width of the strips to be joined processes such as pickling and annealing. together.

An object of the invention is to provide a novel Directly over these stationary and movable die and improved method of joining the ends of metal elements 3 and 4, a punch-supporting frame 5 is strip together by a simple punching and clamping mounted for guided vertical reciprocation be- 10 or stitching operation. tween pairs of spaced guides 6 attached ,to the Another object is to provide an improved appainner faces of the uprights l and 2. The upper ratus for accomplishing the aforementioned oper end of this frame is pivotally attached adjacent ations which is simple and sturdy'of construction, its edges by pins 'la engaged in brackets 10 to a and efficient and dependable in operation. pair of yokes 7 that aremounted upon a pair of These and various other objects as well as the eccentrics 8 provided on a drive shaft 9 supported various other novel features and advantages of in suitable bearings 11 located in the tops of the the invention will be apparent when the following uprights 1 and 2. On the lower end of this punchdetailed description is read in conjunction with supporting frame 5 there is secured a punch carthe accompanying drawings of whichFig. 1 is a rier 12 provided with a plurality of spaced lugs 13 20 plan view of a strip-stitching machine constructed to which the punches 14 are attached, being aflixed in accordance with the invention; Fig. 2 an end thereto in such a way that they maybe easily view of the machine shown in Fig. 1 except for a renewed or repaired. When the shaft 9 is rotated part of the rocking mechanism for the movable the eccentrics 8 and yokes '7 cause the frame 5 to portion of the lower die of the punch press which be reciprocated, moving the punches into and out 25 is shown in section; Fig. 3 a sectional view takenof engagement with the die-forming elements 3 l on the line III-III of Fig. 2; Fig. 4 a sectional .and 4. view taken on the line IV-IV of Fig. 3; Fig. 5 a To firmly hold the strip ends in place during sectional view taken on the line V-V of Fig. 3; the punching operation and effectively prevent 6 a sectional view on larger Sca e taken 0111119 the strips from clinging to the punches as they 30 11118 0f E- F1g-7 afragmenta-l'y Sectlonare pulled out of the dies, a stripping element 21 View Showing the ends of two Pieces of strip in 15 is mounted on the lower end of the frame 5. position in the punch press ready to be connected This Stripper shown in FigS 3 4 is together and mustratingfihe punch jtlst prior to tended across the bottom of the frame 5 and its entry into the strip; Fig. 8 a plan view looking provided with ope 16 through which the 35 down on the Strip and mustratirig in .dotted lines punches 14 are allowed to move. Between its ends tl 1e shape the punch View there is connected to it a plurality of pairs of similar to Fig. '7 but showing the punch at the d itely dis used rods 17 T1185 re lower end of its punching stroke; Fig. 10 a view. Space oppos d1 g h e 40 showing the strip ends after they have been extended upwar oug Sm e opemngs m punched and moved relative to one another sufiilower cross-Piece 18 and the pp O O p ce 40 ciently to lock them together; Fig. 11 a view simi- 21 0f the frame 5 provided w keyed llars lar to Fig. 9 showing the ends of the strips after 19 above the cross-place 18 w ormal y supthey have been locked together asshowninFig. 10, P the r p ju b l w the ends of the 5 but prior to their entry between the compressing D oon these rods 0011 pri 2 are or pinch rolls of the stitching machine; and Fig. provided with their l w e ds bearmg against 12 a view illustrating the stitch after the ends of the collars 19 d their pp ends eneaems suitthe'strip have been passed through the pressing able l ly m unted fi tings 22 disp adJarolls, cent the upper cross-piece 21. Under the influ- Referring in detail to these drawings the numern of u h Springs w the frame 5 is moved 50 als 1 and 2 designate the end uprights, or supportdownwardly the, S pp 15 is yieldingl r ed ing frames of the embodiment of the invention g -in t he nd f the Strips before the P s illustrated. At the base of these uprights on the contact them; and l k w l in h m on entrance side of the machine a plurality of punch the up stroke of the punches until after the dies is provided which consists of a stationary punches are lifted out of contact with the strips, 55

thereby effectively stripping the material from the punches.

As shown in Figs. 4, 7 to 12, inclusive, the I punches 14 are so designed as to punch from the strip ends trapezoidal shaped tongue-like portions 40 and 41 which are attached to the body of the strips at their narrow ends and which have their free ends deflected downwardly sufliciently so that they lie below the lower edge of the lower 10 strip. After these portions are punched from the strips and the punching elements released, the strips are moved relative to each other as shown in Figs. 10 and 11 to thereby lock the two strips together. This locking is produced by the tongues 15 40 and 41 being slid below the body of the strips and as'will be readily appreciated is accomplished with little effort without straining the punched lugs as the sides thereof are tapered outwardly so as to permit them to be so moved without the frictional edge resistance which is encountered when straight sided punchings are employed to produce the stitches.

To facilitate the removal of the strips from the press after the punching operation, the sides I and rear edges of each of the lower punch dies are formed in a movable element 4, which as rshown in Fig. 4 is mounted on a shaft 24 supported in the base of the uprights 1 and 2 and adapted to be rotated out of the path of the punchings,

and 41 as the punch frame 5 is moved away from the strips.

To actuate the die elements 4 in the manner referred to the shaft'24 has keyed to it at one enda crank oryoke-like lever 25 which is in 35 turn'connected at its free end to a pair of pivotally connected links 26 and 27, the latter of which is pivotally secured to a shaft 28 mounted on the outside of the end upright 1. At the union of these two links 26 and 2'1 a flexible connect- '40 ing rod designated generally by the numeral 30 is connected. As shown, this connecting rod comprises a tubular rod 33 which is connected bya fitting 31 formed in its lower end to a pivot 32 to which the two connecting links 26 and 27' are connected. Within the tubular portion 33 of this rod there is arranged a reciprocable plunger 34 which is connected by a, rod 30 to a. yoke 36 pivotally secured to a crank 3'7 provided on the outer end of the punch frame actuating drive shaft 9. Between this lower fitting 31 and an upper fitting 35 located on the upper end of rod 30 there is arranged a helical spring 38 which is utilized to permit the movable die sections 4 to be moved into operative position before the 56 punches of the punch press reach the die and to effect the retraction of such sections out of engagement with the strip after the punches have been removed from the 'die.

In accordance with this construction when the shaft 9 is rotated to move the punch frame-5 downwardly the crank 37 connected to the connecting rod 29 moved in a corresponding direction, causing the link connections 26 and 27 to be moved downwardly, and the lever 25 to be rotated to the left: whereby moving the die ele; ments 4 into their punch-receiving positions which they reach before the crank 37 reaches the lower end of its stroke. As soon as the die sections 4 are in their operative positions the springs 38 begin to flex and take up the further displacement of the rod 30, the compression in such springs which is so established being utilized to assist in holding the die in its operative position. To positively insure the return of the die elements 4 to their inoperative positions on the up stroke of the rod 30 a sleeve 39 is secured to the inside of the tube 33 at its upper end to be engaged by the plunger 34. Hence as the rod 30 is carried upwardly the plunger 34 engages this sleeve 39 and positively lifts the tube 33, thereby returning the die elements 4 to their inoperative positions.

To firmly lock the stitch and thereafter pass the resultant continuous strip out of the press, a pair of pinch or pressure rolls 42 and 43 is provided. These rolls are mounted in suitable bearings 44 and 45 disposed in a pair of windows 46 provided in a rearwardly extending portion of the uprights 1 and 2.

As will be readily appreciated. from an obser vation of Figs. 11 and 12 one or both of the pinch rolls must be yieldably mounted in order to accommodate the overlapped portions of the composite strip as they are moved therebetween. To provide for this in the present structure the upper bearings 45, carrying the upper roll 42, are mounted for vertical adjustment and biased toward the lower roll by a pair of spring coils 43 which have their lower ends engaged in recesses 49 in the tops of the bearings 45 and their upper ends disposed to engage fittings 51 provided at the lower end of a pair of screws 4'7 mounted in the tops of the windows '46, said screws being equipped with non-circular ends 52 for the recep-.

tion of any suitable tool for effecting their adjustment. Depending on the thickness of the strip, the pressure applied by these springs, while suflicient when the rolls are driven to pass the strip through the press, may or may not be sufficient to firmly lock or press the overlapped portions thereof and the stitching flaps together. To provide a positive means for supporting the rolls in carrying out this locking operation an adjustable wedge or stop is arranged between the upper ends of the bearings 45 and shoulders 53 formed in the windows 46. These, wedges each comprise a tapered. bifurcated fitting 54 secured to the top of the-bearing by any suitable means such as screws 50. Mounted above the fitting 54 is a cooperating wedge shaped member 55 which is movable relatively theretoby means of adjusting screw 56. By adjusting the member 55 as will be apparent from Fig. 6 the distance between the top of the member 55 and the shoulder 53 may ,be varied. This distance represents the amount of space required between the rolls to accommodate the overlapped portions of the strip entered between them before the positive pressure is applied. As will be apparent from the above, the

displacement of the rolls necessary to allow for.v

single, double, or triple thickness of the strip may be permitted and after which any further opening of the rolls is prevented by reason of the.

wedge 55 being brought into contact with the shoulder 53 thereby providing a positive resistance for the rolls to lock the stitching flaps together.

To operate the punch press an individual motor 57 is connected to the drive shaft .9 through a suitable gear reducing unit 58 and a flexible. shaft 59. The pinch rolls 42 and 43 are likewise driven by separate motor 61, although this particular driving arrangement is not 118C857 sary. As illustrated, this motor is connected through a reduction unit'62, a pinion stand 63, and the pinions thereof connected by a pair of shafts 64 to the ends of the pinch rolls 42 and 43, flexible coupling 65 being used with such shafts to permit the upper pinch roll to be adjusted without interfering with the drive.

In practicing the invention the leading end 66 of one strip is fed into the punch press in juxtaposition with the trailing end 67 of a preceding strip. When the ends of two strips are thus located with respect to each other the motor 57 is set in motion by any'suitable control, not shown, causing the shaft 9 to rotate. This, as previously described, causes the punch supporting frame 5 to be moved downwardly. Coincident with the downward movement ofthe punching frame, die elements 4 are rotated through the operation of the connecting rod 29 and toggle connections 25, 26 and 2'7 into cooperative position with the stationary member 3, reaching their operative position before the punches reach the strip. During the continued downward movement of the frame 5 the stripper 15 engages the ends of the strips to hold them in place and the punches are passed therethrough, striking from the strips the trapezoidal shaped lugs illustrated in Figs. '7 to 12.

Further rotation of the shaft 9 after the punch operation is completed causes the frame 5 to be moved upwardly toward its position of rest. During this upward movement the punches 14 are first withdrawn from the strip, the stripper 15 remaining in contact with the strip sufliciently long to insure the strip being removed from the punches. In sequence the die elements 4 are pulled away from the strips and are rotated into their inoperative position which allows the unobstructed movement of the overlapped ends of the strip toward the pinch rolls.

At the first movement of the pinch rolls only the strip 67 is moved until the lugs 40 and 41 engage the rear ends of the punch openings in the other strip 66. The two are then moved and the stitch passed through the pinch rolls whereupon the lugs 40 and 41 are firmly pressed against the body of the strips as shown in Fig. 5 to provide a sturdy and firmly locked stitch. Thereafter the two pieces may be passed continuously through a treating operation.

According to the provisions of the patent statutes, I have explained the principle and mode of operation of my invention and have illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as'speciflcally illustrated and-described.

I claim:

1. Apparatus for stitching the ends of two ,metd strips together comprising a punch press equipped with punches adapted to strike from the strip ends when placed therein, tongue-like lugs having outwardly flared side edges and attached to the body of the strips at their narrow ends, and means for moving one of said strips relative to the other after the lugs are formed to lock the strips together and to also firmly press the lugs into engagement with the strip and with each other to enhance the grip of the stitch.

2. Apparatus for stitching the ends of two metal strips together comprising a punch press consisting of a punch mounted on a reciprocable punch carrier, means for reciprocating said carrier, a two-piece die disposed to cooperate with' said punch, a strip clamping and stripping member mounted on said carrier, yieldable means for causing said latter member to clamp the strip to said die in advance of the punch reaching the die and hold said strip until after the punch is removed from it, and means for moving one section of said die into and out of operative position in timed relation with said punch.

3. The method of joining the ends of two pieces of metal strip together consisting of placing the. ends thereof in juxtaposition, striking therefrom superimposed tongue-like lugs having outwardly flared side edges, deflecting the free ends of said lugs below said strip, moving one strip end to lock said lugs against the rear edges of the openings so formed.

4. Apparatus for stitching the ends of two metal strips together comprising a punch press equipped with one or more punches designed to strike from strip mounted thereunder, one or more outwardly flared lugs attached to the strip at the narrow end thereof, a pair of pinch rolls for drawing the strip through the press and tightly locking the stitch formed, means for operating said press, and means for actuating said pinch rolls. 4

5. A strip stitching machine comprising a supporting frame, a punch die mounted in said frame, a punch carrier mounted over said die for vertical reciprocation in said frame, means for reciprocating said carrier, a punch mounted on said carrier which is designed to cooperate with said die to simultaneously strike from two pieces of.

edge of the opening so formed in the lower strip,

means for adJusting said die to permit such movement of the strip, and means for moving the stitched strips out of the press and firmly pressing the stitching lugsagainst the strip to enhance the grip of the stitch.

6. A strip stitching machine comprising a supporting frame, a punch die mounted in said frame consisting of a stationary forward section and an adjustable rearward section, means for pivotally supporting said rearward section, a punch disposed to cooperate with said die to produce a trapezoidal shaped punching attached at its narrower end to the material fromwhich it is cut,

means for operating said punch, means operated in synchronism therewith for moving said adjustable die section into and out of operative position and means for clamping the material to the die and stripping it from said punch.

'7. In a strip stitching machine, a punch press for striking from strip ends mounted thereon stitch-forming lugs, a pair of pinch rolls asso ciated therewith-for pulling the strip through the machine and locking the strip ends together after they are punched, and means for positively determining the extent of separation of said pinch rolls.

' JOHN BIGGERT. 

